From 489c9c3407cbfd473c2f8d7863ffaaf6d2e8fcf8 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Wed, 30 Sep 2020 15:40:23 -0400 Subject: Fix handling of BC years in to_date/to_timestamp. Previously, a conversion such as to_date('-44-02-01','YYYY-MM-DD') would result in '0045-02-01 BC', as the code attempted to interpret the negative year as BC, but failed to apply the correction needed for our internal handling of BC years. Fix the off-by-one problem. Also, arrange for the combination of a negative year and an explicit "BC" marker to cancel out and produce AD. This is how the negative-century case works, so it seems sane to do likewise. Continue to read "year 0000" as 1 BC. Oracle would throw an error, but we've accepted that case for a long time so I'm hesitant to change it in a back-patch. Per bug #16419 from Saeed Hubaishan. Back-patch to all supported branches. Dar Alathar-Yemen and Tom Lane Discussion: https://postgr.es/m/16419-d8d9db0a7553f01b@postgresql.org --- src/backend/utils/adt/formatting.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'src/backend/utils/adt/formatting.c') diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c index b91ff7bb803..3bb01cdb65a 100644 --- a/src/backend/utils/adt/formatting.c +++ b/src/backend/utils/adt/formatting.c @@ -4569,8 +4569,11 @@ do_to_timestamp(text *date_txt, text *fmt, Oid collid, bool std, { /* If a 4-digit year is provided, we use that and ignore CC. */ tm->tm_year = tmfc.year; - if (tmfc.bc && tm->tm_year > 0) - tm->tm_year = -(tm->tm_year - 1); + if (tmfc.bc) + tm->tm_year = -tm->tm_year; + /* correct for our representation of BC years */ + if (tm->tm_year < 0) + tm->tm_year++; } fmask |= DTK_M(YEAR); } -- cgit v1.2.3